Protective device for apparatus subject to fire hazard



June 13, 1933; c. c. WHITTAKER 1,914,187

PROTECTIVE DEVICE FOR APPARATUS SUBJECT TO FIRE HAZARD Filed April 16, 1928 INVENTQR 622%5CM292k 1/ j BY W? F'yj 7 W Patented June 13, 1933 UNlrsn STATES! PATENT QFFECE VANIA PENNSYLVANIA, ASSIGNOR TO WESTING- PROTECTIVE DEVICE FOR AYPABATUS SUBJECT TO FIRE HAZARD Application filed April 16,

My invention relates to protective devices and more especially to means for decreasmg the fire hazard of electric-locomotive transformers.

My invention resides in automatic means for disconnecting electrical apparatus from its supply circuit and immersing said apparatus in a fire-quenching medium in the event of fire therein.

It is characteristic of my invention that it is particularly applicable to electric-locomotive service wherein, in the event of fire in a tunnel, the great volume of smoke incident thereto, which frightens passengers, is prevented.

It is further characteristic of my invention that the apparatus associated therewith is protected from serious damage becauseof fire arising from short circuits and grounds.

In a particularly desirable application of my invention, in electric locomotives, it is customary to transform the electric energy necessary to operate the motors from a relatively high voltage on the trolley to a volt age suitable for the motors by a transformer mounted in the locomotive itself. Such transformers are disposed in a chamber through which a cooling blast of air is continually circulated for removing the heat generated by the transformer and maintaining its temperature below a predeterminer maximum value.

The high-voltage primary wind ngs of such transformers have one termi cl connected to the trolley and the other terminal connected to ground. Sometimes, due to age, ibration and imavoidablo circumstances, breakdowns and failures occur in the insula tion between e windings and ground. Such failures c use arcing which results in rapid combustion of the insulating material and increase in temperature accompanied by large volumes of smoke, which is fanned by the cooling air blast mentioned above.

I provide means for protecting such ap- 1928. Serial No. $370,185.

paratus from in the event of such short circuits and also provide means for preventing the production of the large volumes of smolre mentioned above. More specifically, I provide means for disconnecting the transformer from its supply circuit, means for stopping the cooling air blast, and means for immersing the transformer in a firequenchir medium, automatically, in the event of a temperature exceeding a predetermined maximum valve in the chamber housing the transformer. I

For a specific embodiment of my invention, reference may be had to the accompanying drawing taken in connection with the following description.

In the drawing:

Fig. 1 is a view, in front elevation, partially in cross section, of a locomotive transformer disposed in a chamber.

Fig. 2 is view, in side elevation, of the device shown in Fig. 1, with the addition of my improvement,

Fig. 3 is an enlarged view, in elevation, of the valve and mechanism for opening the same shown in Fig. 2,

Fig. 4 is an enlarged view, in elevation, of the relief valve shown in Fig. 1 for permitting the air in the chamber to be exhausted by the fire-quenching medium,

Fig. 5 is a bottom plan view of the valve shown in Fig. 4, and

Fig. 6 is a view similar toFig. 2 of an electrical modification of means for opening the valve of the fire-quenching container.

In normal operation, the transformer 1, comprising a core 2 and coils 3, is energized by the electrical energy derived from the trolley wire (not shown) through a conductor 4, that conveys current to a terminal bushing 5 mounted on a casing 6. A blower 7 supplies air, under pressure, to the casing 6 through a pipe 8 which flares out to the width of the casing 6 and furnishes air to the whole opening 9. As indicated by the A CCELPORATION OF PENNSYL-' a rows, the air from the blower T circula throughout the chamber 6, reduces the temperature of the transformer 1 and is blown out of the opening 10.

is ointed out above, case of a short circuit. the consequent br ng of the men- 1 l L rating material was aided by the b ZISr volumes of oi iiening 10 i of passeni, 7 1 A snuttn down LllC blower motor Ta, closing the op 9 and 10, and flooding the easing 1 i. .i a the quenching medium such as carbon dioxide when a predetermined inaxiiniuii temperature exceeded.

sible link 11 is zsso to initiate the ope in the even; or a ten1- preceterinined maxi- To this end, a heatelated with the a perature e'iceei mum value.

A; preterable arrangement, as

25 indicated in the drawing, comprises providing the openings l with doors or latch s l2 and 13 respectively. The doors 12 i It ed together by a rod 14 tha ends to arms 15 and 16 39 wl ii'iti secured to the doors 12 and 133, rc-

s e link 11 is connected 1 mounted on the cas- 11 our The link 11 holds tl i 3 '7 open position against the force t a spring 19 that is adapted to exert a force alwa t's tending to close these doors. The axis 1'? is proviled with a drum 20 mounted on one end. The dr am 20 is provided with conducting segments 21 and "5 circuit breaker 2? that are associated. with Lolita and and 25 and 26, ICSPQCLl .ely.

A turning of the drum 20 is adapted to disconnect the conductor by operating a.

circuit of is in tie conductor at.

toggle 28 that held 1 closed position by an 'lectromagnet 29, against the force 01'' a 6 31). The electroniagnet is energized from supply (not shown) through conductors 31, 33 and 35 is presided in the circuit of the conductor for inanuall Y operating the circuit breaker 27. Normally, lectron1agnet 29 is en c and the tra' oriner 1 is in circuit, however, when the drum 20 is rotated, the conducting segi ient 92 n oved from under the contacting and 2, anti, the energizing circuit 29 broken, tlierel y f 30 to open the breaker d non it the cir zuit oi the conduc- *or at and the transformer 1, putting the lattn: out of operation.

In a similar manner the blower motor in is energized from the electrical source i supply through conductors 31, 36, 37 and 5 that are connected in circuit relation ti iroue'n the conducting segment on ta r.

and contacting fingers 23 and 1 ii lation of the drum 20 (llSCOllElCUi he circuit from the source of supply to the blower T and causes a discontnnunce ot the supp as carbon dioxide gas, and

r nib ter to fill the chamber through a connectio pipe 13. The handle 44 ot' the Hilts il loosely connected to the link 39 in the o ing so that the doors 12 and 13 will almostclosed before the lost motion due to the opening 10 is taken up and the valve all snapped open.

When the blower 7 is stopped and the doors 1? and 13 are closed, the chamber 6 is still filled with air. To provide for the proper displacement 01 such air by the carbon-dioxide gas, I place a valve s15 in the upper part of the casing 6 so that, as the carbon dioxide gas enters at the bottom of the chamber, the air is exhausted by way of the valve 45.

The valve 45 preferably comprises a disc 16 that fits snugly inst the surface of the casing to prevent ti e coolingair from escaping through an opening 17 in the latter. The air from the blower 7 causes a pres sure of about 3 or 1 ounces in the chamber which is sufficient to hold the disc 16 tight against the surface of the casing. However, when the blower 7 stops and the doors 12 and 13 are closed, the pressure within the tanks falls which permits gravity to pull the disc 46 away from the wall near the opening 17 to the supporting fingers 48 that are secured to the wall 19. In such position, the air that is displaced by the carbon dioxide gas flows out of the opening 17.

lVhen a predetermined temperature of the r surrounding the fusible link 11 is exreeded. the latte' melts and the spring 19 quickly forces the doors 12 and 1:55 closed. At the same time, the drum 20 rotates and dis onnccts the blower motor 7a. and operates the circuit breaker 27 which disemnects the transformer winding t'roin its source oi supply. The rotation of the shaft 17 also opens the valve 41, and the chambzn' (S is lilled with carbon die ide ojas, the air being exhausted through the valve d5. The closing of the doors 12 and 13, together with the flooding of the casing 1 with carbon dioxide gas, effectually quenches any tendency toward combustion of the insulatill ing material of the transformer 1. The closing of the doors 12 and 13, at the same time, prevents the emission of any smoke. The apparatus is, therefore, fully protected against damage.

In Fig. 6, I show a modification of the method of operating the valve 41 by electrical means instead of mechanical means. In such modification, the drum 20 may be provided with a third conducting segment whi operates to disconnect an elec- ""al circuit through contacting fingers 51 32 when the drum 20 is rotated by the spring 19. The valve 41, insuch case, would comprise the well-known magnet-operated plunger type connected to a source of supply (not shown) through conductors 53 and 54 and the conducting segment 50 on the drum 20. A rotation of the drum 20 causes an operation of the valve 41 to fill the easing 6 with carbon dioxide, in a manner somewhat similar to that outlined above in con nection with a mechanically operated Valve.

My invention is applicable to apparatus other than that described above and I, therefore, wish to be limited only within the scope of the appended claims.

I claim as my invention:

1. In a locomotive transformer disposed in a casing and subject to fire hazard, the combination with means, including a circuit breaker, for disconnecting said transformer from its supply circuit, and means for venti g the atmosphere surrounding said transrormer from said casing and introducing carbon dioxide gas in the event of fire in said transformer.

52. In combination, a casing housing apparatus subject to fire, means for circulating air through said casing for cooling said apparatus, means for stopping said circulation of air, and means for venting air from said casing and flooding said casing with a firequenching medium in case of fire in said apparatus.

3. In combination, a casing, means for circulating air through said casing, and means for stopping said air circulation and displacing the air within said casing with a fire-quenching medium when a predetermined temperature is exceeded in said casing.

4. In combination, an electrical transformer, a casing for said transformer, auton'iatic means responsive to the temperature within said casing for flooding said casing with an air-free fire-quenching gas in the event of a ground or short circuit in said transformer, and venting means arranged to vent the gases displaced by said fire-quenchmg gas.

In combination, electrical apparatus, a casing enclosing said apparatus, means for forcing a fluid through said casing to maintain the temperature of said apparatus befor housing said transformer, means for.

circulating air through said housing means, means actuated upon the temperature of said housing means exceeding a certain value, for stopping the circulation of said air and means for venting the remaining air and introducing a gas having the'firepreventative properties of carbon dioxide.

In testimony whereof, I have hereunto subscribed my name this 12th day of April CHARLES C. WHITTAKER. 

